A variety of microphones are used today in motor vehicles. A microphone array with four microphones, whereby two microphones each are assigned to a driver or a passenger, is thus known from EP 1 695 873 A1. A noise-compensated hands-free kit in motor vehicles in which two directional microphones are installed in the area of a rearview mirror is known from DE 43 15 000 A1. DE 102 17 822 C1 lastly discloses a method and a device for detecting the viewing direction of a person by means of at least one directionally selective microphone.
DE 10 2014 013 919 A1 discloses a microphone system with three microphones arranged in the form of an isosceles triangle at respective corners of the triangle, in which the signals of the first and the second microphone are processed in such a way that a directivity oriented towards the driver's seat is provided and the signals of the second and third microphones are processed to provide a directivity oriented towards a passenger seat. It has been found that a variation in the size of the driver or the passenger entails an undesirable variation in the quality of the signals provided by the microphone system.
The challenge therefore arises to provide a microphone system for a motor vehicle, in which a variation of the signal quality is minimized in the presence of a variation of the size of the driver or the passenger.